• In the Ulaby/Maharbiz text, please continue to study Chapter 9 on frequency response and filters.
• Please read Chapter 13 (Sections 1-4) on Magnetically Coupled Circuits, which is available as a pdf file on Blackboard under Course Materials, in the folder "Materials from Ulaby & Maharbiz textbook." We won't do three-phase transformers in Section 13-5. Also look at pages 202-204 in Chapter 5 (inductors) and pages 346-347 in Chapter 7 (an application of transformers in power supplies).

The exam will be closed-book and closed-notes, but you can bring your calculator and one piece of 8.5" by 11" paper with notes and formulas (you can write on both sides of the paper).

Please read the four page handout before class on Tuesday, Feb. 22 (I will bring printed copies to class). Then submit the following answers in class on Thursday, Feb. 24.

• For the crossover network with two speakers (LP and HP filters), answer questions 1a, 1b, and 1c. You do not have to submit any Bode plots, but provide brief written answers to the questions.
• For the crossover network with three speakers (LP, BP, and HP filters), answers questions 2a-2e. Specify your choice for B that provides the "flattest" gain, the corresponding filter cutoff frequencies, and explain how you obtained values for L and C for each filter to achieve the design. Then provide the Bode plots from filter_RLC.m showing that your L and C values achieve a desirable total frequency response. Explain how adding the mid-range speaker (and BP filter) improves the response compared with the design that uses only LP and HP filters. (Or, does the mid-range improve the total response? Explain whether you think adding the mid-range speaker improves or degrades the total response.)
• We will discuss in class on Feb. 24 how an equalizer can further improve the frequency response by adding a gain to the BP filter. If you have some ideas how this would work, try it out in Matlab (but this is not required).
  An even better solution is to add a resistor to the BP filter and switch the polarity on the mid-range speaker attached to the BP filter output (creating a phase shift of 180 degrees). We will talk about this on Feb. 24.